Objective: To determine the prevalence of obesity and reference percentile curves of body mass index (BMI; kg/m2) in Japanese adults.
Design: Cross-sectional nationwide surveys (The National Nutrition Survey, Japan) carried out in 1990-1994. A sample of 23,556 males and 28,751 females aged 15-84 y was used for this analysis.
Results: The prevalence of grades 1 (BMI: 25.0-29.9), 2 (30.0-39.9) and 3 (> or = 40.0) overweight, was estimated to be 24.3%, 1.84% and 0.019% in males, respectively, and 20.2%, 2.87% and 0.032% in females, respectively, subjects aged 35-64 y after standardization to the age-distribution of the standard world population (WHO, 1993). The age-standardized prevalence of obesity (for BMI > or = 26.4, a criterion of the Japan Society for the Study of Obesity; and > or = 30.0 was 13.6% and 1.86% in males, respectively, and 13.5% and 2.90% in females, respectively, subjects aged 35-64 y.
Conclusions: The standardized prevalence of obesity (BMI > or = 30.0) in Japanese adults was quite low compared with the data in western populations.